Self-cooling bus-system for electrical installations



March 10, 1936. w SHOEMAKER 2,033,743

SELF COOLING BUS SYSTEM FOR ELECTRICAL INSTALLATIONS Filed Oct. 2, 19342 Sheets-Sheet l 6 "75 78 i5 -fiyj GENERATOR NQ 3 SF] In GENERATOR NO IGENERATOR No.2 GENERATOR No.3

March 10, 1936. R. w. SHOEMAKER 2,033,743

I SELF COOLING BUS SYSTEM FOR ELECTRICAL INSTALLATIONS Filed Oct. 2,1954 2 Sheets-Sheet 2 T0 TRANSFORNfiRS 7/ MVW GENERATOR NO 2 GENERATORN01 Patented Mar. 10, 1936 UNITED STATES PATENT OFFICE SELF-COOLINGBUS-SYSTEM FOR ELECTRICAL INSTALLATIONS Application October 2, 1934,Serial No. 746,504 6 Claimsf 01.173-13 This invention relates tobus-systems for electrical installations and particularly toself-cooling bus-systems for such installations.

One of the major problems in bus-systems has been to eifectivelydissipate the extensive and undesirable heat developed therein as anincident to the flow of high currents therethrough. Such heat not onlymaterially decreases the conductivity of the system but also producessuch degrees of expansion, etc., as tend to mechanically disrupt thesystem and which it is difficult to com.- pensate for without unduecomplexity of supports, guides, braces, etc.

Efforts have heretofore been made to dissipate the heat referred to byproviding composite busbars, the component elements of which have beenspaced from each other in the hope that crosswise movement of airtherebetween would ameliorate the condition referred to. Very completeand exhaustive tests have shown, however, that the amount of heatdissipated by such composite bus-bars with their laterally-spacedelements is so relatively negligible as not to be worth the effort andcomplexity necessary to their construction and installation.Furthermore, protective coverings, supports, etc., have served to blockoff or retard the lateral flow of air, thereby further minimizing thealready negligible cooling effect. One of the objects of the presentinvention is to provide a superior bus-system which will be self-coolingto an eflective degree.

A further object is to provide a superior bussystem in which coolingcurrents of air will be caused to flow lengthwise of the bus-bars at 5Velocities sufilcient to effectively cool the same.

Other objects and advantages will appear to those skilled in the artfrom the following, considered in conjunction with the accompanyingdrawings and the appended claims.

40 In the accompanying drawings:

Fig. 1 is a schematic top or plan view of one form which a bus-systemembodying the present invention may assume;

Fig. 2 is a view thereof, in front elevation;

5 Fig. 3 is a view thereof in end elevation;

Fig. 4 is a transverse sectional view showing a two-part tubularbus-bar; and

Fig. 5 is a schematic representation of another form of convectorbus-system embodying the 50 present invention.

The bus-system schematically shown in Figs. 1 to 3 inclusive is designedto serve in connection with a plurality of three-phase generators, threeof which latter are indicated. The particular 55 bus-system hereinchosen for illustration in the said figures includes three correspondingsets of horizontal tubular feeder-runs, respectively comprising paralleltubes Ill lll 10, ll ll H and l2 l2 !2 The horizontal runs referred toare preferably of rectangular cross-section, and may 5 be formed ofsolid drawn tubes, as shown in Figs. 1 to 3 inclusive, or may be builtup of sections organized into a tubular unit as shown in Fig. 4, thedesired characteristic being flue-like tubes or air-conduits free orsubstantially free of lateral 14 openings of such extent as would permita sufiicient amount of air to leak laterally inwardly to disrupt thelongitudinal high-velocity cooling effeet to be later described.

The outer or forward ends of the set of hori- 15 zontal feeder-runs Ill[0 H3 are connected in a suitable manner to a three-phase generatormarked Generator No. 1 in the accompanying drawings. Similarly, thehorizontal feeder-runs bearing the reference characters H H H serve 20 athree-phase generator marked Generator No. 2, while the correspondingruns bearing reference characters l2 12 l2 serve, in turn, to connect athree-phase generator marked Generator No. 3 into the system.

The respective rear ends of the set of horizontal feeder-runs Ill [0 H!are secured by suitable coupling-plates to upstanding feeder-runs l3 [3I 3, connected, in turn, at their respective upper ends to the adjacentends of horizontal 3o tubularruns I4 M M which latter, for convenienceof description, may be designated as collector-runs. The opposite endsof the horizontal collector-runs I 4 I 4 I 4 are connected to therespective rear ends of the horizontal feederruns Il l2 I2 by means ofvertical tubular feeder-runs l5 l5 15. The respective central portionsof the collector-runs M M |4 are, in turn, connected to the respectiverear ends of the horizontal feeder-runs H I l H by means of verticaltubular feeder-runs I6 H5 I6 Upstanding from the center of therespective collector-runs I 4 M |4 are vertical tubular main-runs l1 I'II! which are of relativelylarger size and of heavier material than thepreviously-described runs, for the reason that they must convey theentire current output of all three of the generators I, 2 and 3.

By reference to Fig. 3 in particular, it will be, noted that therespective upper end of each of thevertical main-runs I'l l'l I! is opento permit the egress of heated air in a manneras will be hereinafterdescribed. Extending rearwardly from each of the said vertical main-runsl1 II I! respectively, are horizontal tubular mainoutlet forinitially-cool air entering the unit comprising the runs I l Ill l3 IlH5 l2 I5 through the open outer or forward ends of the horizontalfeeder-runs Ill ll I2 In a similar manner the open upper end of thevertical main run ll serves as an outlet for air entering the unitcomprising the runs M lo l3 ll I6 [2 l5 through the open forward oroulter ends of the horizontal feeder-runs lfl ll Likewise, the openupper end of the vertical main-run [1 serves as an outlet for the airentering the unit comprising the runs l4 Ill l3 ll l6 l2 l5 through theopen forward or outer ends of the horizontal feeder-runs I0 II H Inaddition to serving as centsor chimneys for the various runs abovedescribed, the vertical main-runs ll IT" I! respectively serve as ventsfor air passing as indicated in Fig. 3 from the rearwardly-extendinghorizontal main-runs l8 l8 l8.

When heating occurs, due to the passage of current through the varioustubular bus-runs, the air within the same will become heated and alongitudinal draft of. air will be drawn through each tubular unit bythe convector action provided by the cumulative chimney efiect of thevarious vertical runs. This air will travel at a relatively-highvelocity due to the convector action already referred to, which velocitywill be boosted, so to speak, by each of the various vertical runsforming part of a given flue-like bus-unit. This effect is made possibleby having the various runs both vertical and horizontal, free orsubstantially free of interior obstructions and of lateral openings,which latter in particular, if present in the structure, would tend toinhibit or otherwise interfere with the convector action referred to,which is exceedingly efficient in cooling the various tubular units ofthe system.

In the schematic representation of the bussystem, many spacing andbracing insulators have been omitted for clarity of illustration. Therequired number and location of insulators to form a sufiicientlyrigid-structure will be obvious to those skilled in the art, as willalso be the location of expansion-joints l9, etc., such as are shown inthe collector-runs le M H5 and which expansion-joints may be duplicatedin accordance with well understood practice wherever they are needful,and no effort has been made to show all of the expansion-joints, etc.,which might be desired in the various runs of the system.

In Figs. 1 to 3 inclusive, the tubular bus-members are shown as solid incross-section, but the same, if desired and for convenience ofconstruction and erection, may be built up of sections as illustrated inFig. 4., so long as they preserve a substantially-continuous tubularstructure in contradistinction to laterally-spaced members providingtransverse air-passages which would preclude the successful operation ofthe highly-effective convector action before described.

In bus installations which terminate in horizontal runs such asillustrated in Fig. 5, it is de-. sirable to provide a chimney or stacksuch as 29, in order to build up a maximum draft or convector action andthus induce a rapid movement of air longitudinally through the variousruns of the bus-system.

It has been found that by assembling together both vertical andhorizontal tubular elements having their interior passagesinterconnected and free or substantially free of both interiorobstructions and lateral leakage, a cooling effect is obtained which sofar exceeds the cooling effect obtained by lateral ventilation asheretofore proposed, as to render the latter comparatively negligible.

The various runs of the bus-system may be referred to as beingimperforate or substantially imperforate for the reason that althoughcertain openings for bolts, rivets, etc., may be formed therein, thesaid openings are so effectively closed as to provide interconnectedangularly-disposed air-ducts sufficiently free of lateral air-openingsas to function as described.

The invention may be carried out in other specific ways than thoseherein set forth without departing from the spirit and essentialcharacteristics of the invention, and the present embodiments aretherefore to be considered in all respects as illustrative and notrestrictive, and all changes coming within the meaning and equivalencyrange of the appended claims are intended to be embraced therein.

I claim:

1. A bus-system comprising: a substantiallyhorizontal tubular bus-memberproviding a substantially-imperforate air-duct; and asubstantially-vertical tubular bus-member extending from the saidsubstantially horizontal bus-memher and also providing asubstantially-imperferate air-duct; the said substantially-horizontalbus-member and the said substantially-vertical bus-member having theirinterior passages connected in a substantially-air-tight manner toprovide a continuous angular air-duct; the lowermost one of saidbus-members having an airinlet opening, and the uppermost one thereofhaving an air-egress opening located in a plane above the air-inletopening of the other of said bus-members; whereby, upon the bus-systembecoming heated by the passage of current therethrough, the saidsubstantially-vertical busmember will act as a convector and forcecooling air not only through itself, but through the saidsubstantially-horizontal bus-member to cool both of the same by alongitudinally-flowing highvelocity air-current. V

2. A bus-system comprising: a substantiallyhorizontal tubular bus-memberproviding a substantially-imperforate air-duct; and asubstantially-vertical tubular bus-member upwardly extending from thesaid horizontal bus-member and also providing asubstantially-imperforate airduct; the said substantially-horizontalbus-member and the said substantially-vertical bus-member extendingupwardly therefrom having their interior passages connected in asubstantiallyair-tight manner to provide a continuous angular air-duct;the said substantially-horizontal busmember having an air-inlet openingat a point remote from its connection to the said substantially-verticalbus-member, which latter is provided in a plane above the said horizonhastiall'y-vertical bus-members having its interior passage connected ina substantially-air-tight manner to the interior passage of the saidsubstantially-horizontal bus-member and each having an air-inletopening; the said substantially-horizontal bus-member having anair-egress opening located above the air-inlet openings of saidsubstantially-vertical bus-members; whereby, upon the bus-systembecoming heated by the passage of current therethrough, the saidsubstantially-vertical bus-members will act as convectors and forcecooling air not only through themselves, but through the saidsubstantiallyhorizontal bus-member.

4. A bus-system comprising: a substantiallyhorizontal tubular bus-memberproviding a substantially-imperforate air-duct; a substantiallyverticaltubular bus-member downwardly extending from the saidsubstantially-horizontal bus-member and also providing asubstantiallyimperforate air-duct; and a substantially-vertical tubularbus-member upwardly-extending from the said substantially-horizontalbus-member and providing a substantially-imperforate airduct; both ofthe said substantially-vertical busmembers having their interiorpassages connected in a substantially-air-tight manner to the interiorof the said substantially-horizontal busmember to provide a continuousair-duct, in which the latter bus-member is included; the downwardlyextending one of the said substantiallyvertical bus-members having anair-inlet opening and the upwardly extending one thereof having anair-egress opening located above the air inlet opening of saiddownwardly-extending busmember; whereby, upon the bus-system becomingheated by the passage of current therethrough, the saidsubstantially-vertical busmembers will act as convectors and forcecooling air through the system to cool the same.

5. A bus-system comprising: a substantiallyhorizontal tubular bus-memberproviding a substantially-imperforate air-duct and having an air-inletopening; a plurality of substantiallyvertical tubular bus-membersextending from the said substantially-horizontal bus-member and alsoproviding substantially-imperforate airducts, and connected in asubstantially-air-tight manner to the interior of the saidsubstantiallyhorizontal bus-member; at least one of the saidsubstantially-vertical tubular bus-members extending upwardly from thesaid substantiallyhorizontal bus-member and having an air egress openinglocated above the air-inlet opening of the said substantially-horizontalbus-member.

6. A bus-system comprising: a substantiallyhorizontal tubular collectorbus-member providing a substantially-imperforate air-duct; a pluralityof substantially-vertical tubular feeder busmembers' downwardlyextending from the said substantially-horizontal bus-member and alsoproviding substantially-imperforate air-ducts; a substantially-verticaltubular main bus-member upwardly extending from the said collectorbusmember and also providing a substantially-imperforate air-duct; thesaid tubular main busmember and the said tubular feeder bus-membershaving their interior passages connected in a substantially-air-tightmanner to the interior passage of the said substantially-horizontalcollector bus-member; the said feeder bus-members each having anair-inlet opening and the said upwardly extending main bus-member havingan air-egress opening located above the air-inlet openings of the saidfeeder bus-members; whereby, upon the bus-system becoming heated by thepassage of current therethrough, the said substantially-verticalbus-members will act as convectors and force cooling air through thebussystem to cool the same.

RICHARD W. SHOEMAKERL

